STPC12 datasheet(38/111 Pages) STMICROELECTRONICS

38 / 111 page

STRAP OPTION

38/111

Issue 1.0 - July 24, 2002

3.1.4. STRAP REGISTER 2

This register is read only with the exception of bit 4

STRAP2

Access = 0022h/0023h

Regoffset =04Ch

76543210

MD[53]

MD[52]

RSV

MD[20]

MD[19]

MD[18]

MD[51]

MD[50]

This register defaults to the values sampled on the MD pins after reset

Bit Number Sampled

Mnemonic

Description

Bit 7

MD[53]

This bit reflects the value sampled on MD[53] pin and determines

whether the internal Parallel Port Controller is used

0: Internal Parallel Port Controller is disabled

1: Internal Parallel Port Controller is enabled

Bit 6

MD[52]

This bit reflects the value sampled on MD[52] pin and determines

whether the internal Keyboard controller is used

0: Internal Keyboard Controller is disabled

1: Internal Keyboard Controller is enabled

Bit 5

Rsv

Reserved

Bit 4

MD[20]

This bit reflects the value sampled on MD[20] pin and controls the Dot

clock pin (DCLK) direction as follows:

0: Input.

1: Output of the internal frequency synthesizer DCLK PLL.

Bit 3

MD[19]

This bit reflects the value sampled on MD[19] pin and controls the

Memory clock output pin (MCLKO) as follows:

0: Tristated.

1: Output of the internal frequency synthesizer MCLKO PLL.

Bit 2

MD[18]

This bit reflects the value sampled on MD[18] pin and controls the Host

clock pin (HCLK) direction as follows:

0: Input.

1: Output of the internal frequency synthesizer HCLK PLL.

Bit 1

MD[51]

This bit reflects the value sampled on MD[51] pin and determines

whether the internal UART1 is enabled:

0: Internal UART1 is disabled

1: Internal UART1 is enabled

Bit 0

MD[50]

This bit reflects the value sampled on MD[50] pin and determines

whether the internal UART2 is enabled:

0: Internal UART2 is disabled

1: Internal UART2 is enabled

STPC12 数据表(PDF) 38 Page - STMicroelectronics

STPC12 数据表(HTML) 38 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载